JPH0923576A - Electric shock preventive circuit - Google Patents
Electric shock preventive circuitInfo
- Publication number
- JPH0923576A JPH0923576A JP7172243A JP17224395A JPH0923576A JP H0923576 A JPH0923576 A JP H0923576A JP 7172243 A JP7172243 A JP 7172243A JP 17224395 A JP17224395 A JP 17224395A JP H0923576 A JPH0923576 A JP H0923576A
- Authority
- JP
- Japan
- Prior art keywords
- load
- voltage
- unit
- power supply
- section
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Television Receiver Circuits (AREA)
- Transforming Electric Information Into Light Information (AREA)
- Direct Current Feeding And Distribution (AREA)
- Control Of Voltage And Current In General (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、例えば、ＰＤＰ（Plas
ma Display Panel) のように高電圧で駆動される負荷の
残留高電圧を、端子解放時に急速放電することにより放
電前の電圧に触れることを防ぐ感電防止回路に関する。The present invention relates to, for example, PDP (Plas
It relates to an electric shock prevention circuit that prevents the residual high voltage of a load driven by a high voltage such as a ma Display Panel) from being exposed to the voltage before discharge by rapidly discharging when the terminals are released.
【０００２】[0002]
【従来の技術】ＰＤＰシステムを例にして説明する。図
４に示すように、ＰＤＰシステムは商用電源（A.C)を複
数の直流に変換する外部電源部１と、前記直流により駆
動される、例えば、リモコン受信部、システム制御マイ
コンのように低電圧で動作する第一負荷部２と、前記外
部電源部１が供給する直流により駆動される、例えば、
パネルのように高電圧で動作する第二負荷部３と、前記
外部電源部１の直流毎に相応の負荷部に電力を伝達する
コネクタを備えた１本のケーブル４とで構成される。2. Description of the Related Art A PDP system will be described as an example. As shown in FIG. 4, the PDP system includes an external power source unit 1 for converting a commercial power source (AC) into a plurality of direct currents, and a low voltage such as a remote control receiver or a system control microcomputer driven by the direct currents. Driven by the operating first load unit 2 and the direct current supplied from the external power supply unit 1, for example,
It is composed of a second load section 3 that operates at a high voltage like a panel, and one cable 4 provided with a connector for transmitting power to a corresponding load section for each DC of the external power supply section 1.
【０００３】外部電源１からＰＤＰパネル（第二負荷）
３に、例えば、１８０Ｖの駆動用高電圧電源が供給され
る。ところが、前記パネル３に映像を表示中にケーブル
４のコネクタを誤って抜いた場合、同ケーブルのコネク
タは接続ピンが突出する形状で、誤って手に触れやすい
ので、ＰＤＰパネル（第二負荷）３内部の放電前の蓄積
している電圧に触れる恐れがあった。External power source 1 to PDP panel (second load)
For example, a driving high-voltage power supply of 180 V is supplied to 3. However, if the connector of the cable 4 is accidentally unplugged while the image is displayed on the panel 3, the connector of the cable has a shape in which the connection pin is protruded, and it is easy to accidentally touch the PDP panel (second load). 3 There was a risk of touching the accumulated voltage before discharge inside.
【０００４】[0004]
【発明が解決しようとする課題】本発明は上記問題点に
鑑みなされたもので、直流の供給が停止されたことを検
知して、負荷の残留高電圧を急速放電させる感電防止回
路を提供することを目的とする。SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides an electric shock preventive circuit which detects that the supply of direct current is stopped and rapidly discharges the residual high voltage of the load. The purpose is to
【０００５】[0005]
【課題を解決するための手段】上記目的を達成するため
に、商用電力を入力し直流を生成出力する電源部と、低
電圧で駆動される第一負荷部と、高電圧で駆動される第
二負荷部と、前記電源部と前記第一負荷部及び第二負荷
部とを接続するケーブルと、前記第一負荷部の電源線の
電圧を検出し結果を出力する検出部と、前記第二負荷部
の電源線と接地間に接続するとともに前記検出部の結果
に基づき動作するスイッチ部とで構成し、前記検出部が
所要の電圧を検知したとき、前記スイッチ部を遮断状態
から導通状態にする。In order to achieve the above object, a power supply section for inputting commercial power and generating and outputting direct current, a first load section driven by a low voltage, and a first load section driven by a high voltage. A second load unit, a cable connecting the power supply unit to the first load unit and the second load unit, a detection unit that detects the voltage of the power supply line of the first load unit and outputs the result, and the second The switch section is connected between the power line of the load section and the ground and operates based on the result of the detection section.When the detection section detects a required voltage, the switch section is changed from the cut-off state to the conductive state. To do.
【０００６】[0006]
【作用】以上のように構成したので、電子機器を動作中
にケーブルを誤って抜いた場合、検出部が低電圧で駆動
される第一負荷部の電源線の所要電圧を検出し、その結
果、スイッチ部を遮断状態から導通状態にすることによ
り、高電圧で駆動される第二負荷部の電源線を接地し、
同第二負荷部の残留高電圧を急速に放電するので、前記
ケーブルのコネクタの接続ピンにつながる電源線は０電
圧になり、同接続ピンに触れても放電前の電圧に触れる
恐れがない。With the above configuration, when the cable is accidentally pulled out while the electronic device is in operation, the detection unit detects the required voltage of the power supply line of the first load unit driven by a low voltage, and the result , The power supply line of the second load unit driven by a high voltage is grounded by switching the switch unit from the cut-off state to the conductive state,
Since the residual high voltage of the second load portion is rapidly discharged, the power supply line connected to the connection pin of the connector of the cable becomes 0 voltage, and even if the connection pin is touched, there is no fear of touching the voltage before discharge.
【０００７】[0007]
【実施例】以下、本発明による感電防止回路について、
図を用いて詳細に説明する。図１は、本発明による感電
防止回路の実施例ブロック図である。１は商用電力（A.
C 100V等) を入力し、直流、例えば、D.C 5Vと、D.C 18
0Vとを生成し出力する外部電源部である。２は低電圧で
駆動される、例えば、リモコン受信回路、システム制御
マイコン回路のように、D.C 5Vで動作する第一負荷部で
ある。３は高電圧で駆動される、例えば、ＰＤＰパネル
のようにD.C 180Vで動作する第二負荷部である。４は、
前記外部電源部１と、前記第一負荷部２の電源線及び、
第二負荷部３の電源線とを接続する１本のケーブルであ
る。５は、前記第一負荷部２の電源線の電圧を検出する
検出部である。６は、前記第二負荷部３の電源線と接地
間に接続したスイッチ部である。Embodiments of the electric shock prevention circuit according to the present invention will be described below.
This will be described in detail with reference to the drawings. FIG. 1 is a block diagram of an embodiment of an electric shock prevention circuit according to the present invention. 1 is commercial power (A.
C 100V, etc., and input DC, for example DC 5V and DC 18
It is an external power supply that generates and outputs 0V. Reference numeral 2 is a first load unit driven by a low voltage, for example, a remote control receiving circuit and a system control microcomputer circuit, which operates at 5V DC. Reference numeral 3 denotes a second load unit driven by a high voltage, for example, a PDP panel, which operates at DC 180V. 4 is
The external power supply unit 1, the power supply line of the first load unit 2, and
It is one cable that connects to the power supply line of the second load unit 3. Reference numeral 5 is a detection unit that detects the voltage of the power supply line of the first load unit 2. 6 is a switch section connected between the power line of the second load section 3 and the ground.
【０００８】図２は、本発明による感電防止回路の検出
部５と、スイッチ部６との具体的な回路図である。５１
は第一負荷部２の電源線Ａにアノードを接続した（順方
向）ダイオードである。５２は一端を、前記ダイオード
５１のカソードに接続するとともに、他端を接地したコ
ンデンサである。５３は、前記ダイオード５１のカソー
ドにエミッタを接続するとともに、ベースを前記電源線
Ａに接続し、かつ、コレクタを抵抗５４を介して接地し
たＰＮＰトランジスタである。５４は抵抗である。６１
はエミッタを接地するとともに、ベースを前記検出部５
のＰＮＰトランジスタ５３のコレクタに接続し、かつ、
コレクタを前記第二負荷部３の電源線Ｄに接続したＮＰ
Ｎトランジスタである。FIG. 2 is a specific circuit diagram of the detection unit 5 and the switch unit 6 of the electric shock prevention circuit according to the present invention. 51
Is a diode (forward direction) whose anode is connected to the power supply line A of the first load unit 2. A capacitor 52 has one end connected to the cathode of the diode 51 and the other end grounded. Reference numeral 53 is a PNP transistor whose emitter is connected to the cathode of the diode 51, whose base is connected to the power supply line A, and whose collector is grounded via a resistor 54. 54 is a resistance. 61
Grounds the emitter and connects the base to the detection unit 5
Connected to the collector of the PNP transistor 53 of
NP with the collector connected to the power line D of the second load section 3
N transistor.
【０００９】本発明による感電防止回路の動作を図３の
タイムチャート及び、図１、図２を参照して説明する。
「コネクタ離脱」が発生した時の検出部５の動作を説明
する。図３に示したように、第一負荷部２の電源線Ａの
電圧D.C 5Vは、第一負荷部２の小さな容量と、接地経路
の比較的小さな抵抗値とで決まる小さい時定数で急速に
放電することにより０電圧となる。また、図３に示した
ように、ダイオード５１のカソード電圧Ｂは、ダイオー
ド５１の非常に大きな逆方向抵抗値、例えば、10ＭΩな
どと、コンデンサ５２の所要の容量とで決まる大きい時
定数でゆっくり放電する。前記電源線Ａの電圧と、前記
カソード電圧Ｂとの差の電圧がベース−エミッタ間に印
加されているので同印加電圧が、例えば、０．５Ｖ以上
になったとき、ＰＮＰトランジスタ５３が導通すること
になる。従って、図３に示したように、前記ＰＮＰトラ
ンジスタ５３のコレクタの電圧Ｃは急速に立ち上がり、
カソード電圧Ｂとほぼ等しくなる。The operation of the electric shock prevention circuit according to the present invention will be described with reference to the time chart of FIG. 3 and FIGS.
The operation of the detection unit 5 when the "connector disconnection" occurs will be described. As shown in FIG. 3, the voltage DC 5V of the power supply line A of the first load unit 2 rapidly increases with a small time constant determined by the small capacitance of the first load unit 2 and the relatively small resistance value of the ground path. It becomes 0 voltage by discharging. In addition, as shown in FIG. 3, the cathode voltage B of the diode 51 is slowly discharged with a large time constant determined by a very large reverse resistance value of the diode 51, for example, 10 MΩ and the required capacity of the capacitor 52. To do. Since the voltage of the difference between the voltage of the power supply line A and the cathode voltage B is applied between the base and the emitter, when the applied voltage becomes, for example, 0.5 V or more, the PNP transistor 53 becomes conductive. It will be. Therefore, as shown in FIG. 3, the collector voltage C of the PNP transistor 53 rises rapidly,
It is almost equal to the cathode voltage B.
【００１０】次に、スイッチ部６の動作を説明する。Ｎ
ＰＮトランジスタ６１は、前記ＰＮＰトランジスタ５３
のコレクタの電圧Ｃをベースに供給するように接続して
いるので、前記ＰＮＰトランジスタ５３が導通状態にな
り、ベース電圧が０．５Ｖ以上になったとき導通する。
従って、図３に示したように、前記第二負荷部３の電源
線Ｄは低抵抗値で接地されることになり、急速に０電圧
となる。Next, the operation of the switch section 6 will be described. N
The PN transistor 61 is the PNP transistor 53.
Since the collector voltage C is connected to the base to supply it to the base, the PNP transistor 53 becomes conductive, and becomes conductive when the base voltage becomes 0.5 V or higher.
Therefore, as shown in FIG. 3, the power supply line D of the second load section 3 is grounded with a low resistance value and rapidly becomes 0 voltage.
【００１１】[0011]
【発明の効果】以上説明したように、本発明は直流の供
給が停止されたことを検知して、負荷の残留高電圧を急
速に放電させる感電防止回路を提供する。従って、例え
ば、ＰＤＰシステムにおいて、外部電源と、パネルとを
接続する電源ケーブルを動作中に誤って抜いた場合、同
ケーブルのコネクタの接続ピンに手で触れても、ＰＤＰ
内部の容量に蓄積している残留高電圧が、瞬時に本発明
の感電防止回路を経由して放電されているので、放電前
の電圧に触れる恐れが起こらないメリットがある。As described above, the present invention provides an electric shock preventive circuit which detects that the supply of direct current is stopped and rapidly discharges the residual high voltage of the load. Therefore, for example, in a PDP system, if the power cable for connecting the external power source and the panel is accidentally pulled out during operation, even if the connection pin of the connector of the cable is touched by hand, the PDP
Since the residual high voltage accumulated in the internal capacitance is instantly discharged via the electric shock prevention circuit of the present invention, there is an advantage that the voltage before discharge is not touched.
【図１】本発明による感電防止回路の実施例ブロック図
である。FIG. 1 is a block diagram of an embodiment of an electric shock prevention circuit according to the present invention.
【図２】本発明による感電防止回路の検出部と、スイッ
チ部との具体的な回路図である。FIG. 2 is a specific circuit diagram of a detection unit and a switch unit of the electric shock prevention circuit according to the present invention.
【図３】本発明による感電防止回路の放電動作を説明す
るタイムチャートである。FIG. 3 is a time chart explaining the discharge operation of the electric shock prevention circuit according to the present invention.
【図４】従来のＰＤＰシステムの実施例ブロック図であ
る。FIG. 4 is a block diagram of an example of a conventional PDP system.
１ 電源部 ２ 第一負荷部 ３ 第二負荷部 ４ ケーブル ５ 検出部 ６ スイッチ部 ５１ ダイオード ５２ コンデンサ ５３ ＰＮＰトランジスタ ５４ 抵抗 ６１ ＮＰＮトランジスタ 1 Power Supply Section 2 First Load Section 3 Second Load Section 4 Cable 5 Detection Section 6 Switch Section 51 Diode 52 Capacitor 53 PNP Transistor 54 Resistor 61 NPN Transistor
Claims (3)
源部と、低電圧で駆動される第一負荷部と、高電圧で駆
動される第二負荷部と、前記電源部と前記第一負荷部及
び第二負荷部とを接続するケーブルと、前記第一負荷部
の電源線の電圧を検出し結果を出力する検出部と、前記
第二負荷部の電源線と接地間に接続するとともに前記検
出部の結果に基づき動作するスイッチ部とで構成し、前
記検出部が所要の電圧を検知したとき、前記スイッチ部
を遮断状態から導通状態にすることを特徴とした感電防
止回路。1. A power supply unit for inputting commercial power and generating and outputting DC, a first load unit driven by a low voltage, a second load unit driven by a high voltage, the power supply unit and the first unit. A cable connecting the load part and the second load part, a detection part that detects the voltage of the power supply line of the first load part and outputs the result, and a connection between the power supply line of the second load part and ground. And a switch unit that operates based on the result of the detection unit, and when the detection unit detects a required voltage, switches the switch unit from a cut-off state to a conductive state.
方向に接続したダイオードと、前記ダイオードのカソー
ドに一端を接続するとともに他端を接地したコンデンサ
と、前記ダイオードのカソードにエミッタを接続すると
ともに、ベースを前記第一負荷部の電源線に接続し、か
つ、コレクタを抵抗を介して接地したＰＮＰトランジス
タとで構成したことを特徴とする請求項１記載の感電防
止回路。2. A diode having the detection unit connected in a forward direction to a power supply line of a first load unit, a capacitor having one end connected to the cathode of the diode and the other end grounded, and an emitter connected to the cathode of the diode. 2. The electric shock prevention circuit according to claim 1, further comprising a PNP transistor having a base connected to a power supply line of the first load section and a collector grounded via a resistor.
とともに、ベースを上記検出部の検出結果を入力するよ
うに接続し、かつ、コレクタを上記第二負荷部の電源線
に接続したＮＰＮトランジスタで構成したことを特徴と
する請求項１記載の感電防止回路。3. An NPN transistor in which the switch section is connected to the ground, the emitter is grounded, the base is connected to receive the detection result of the detection section, and the collector is connected to the power supply line of the second load section. The electric shock prevention circuit according to claim 1, which is configured.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7172243A JPH0923576A (en) | 1995-07-07 | 1995-07-07 | Electric shock preventive circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7172243A JPH0923576A (en) | 1995-07-07 | 1995-07-07 | Electric shock preventive circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0923576A true JPH0923576A (en) | 1997-01-21 |
Family
ID=15938278
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7172243A Pending JPH0923576A (en) | 1995-07-07 | 1995-07-07 | Electric shock preventive circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0923576A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014158365A (en) * | 2013-02-15 | 2014-08-28 | Japan Radio Co Ltd | Dc power feeding system |
-
1995
- 1995-07-07 JP JP7172243A patent/JPH0923576A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014158365A (en) * | 2013-02-15 | 2014-08-28 | Japan Radio Co Ltd | Dc power feeding system |
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